Electrochemical machining is a method of removing metal by an electrochemical process. It is typically used for working electrically conductive materials that are extremely hard or that are difficult to machine using conventional methods. For example, electrochemical machining is used to produce complicated shapes such as compressor blades with good surface finish in difficult to machine materials.
Electrochemical machining is often characterized as “reverse electroplating”, in that it removes material instead of adding it. During electrochemical machining, metal is dissolved from a workpiece with direct current at a controlled rate in an electrolytic cell. The workpiece serves as the anode and is separated by a gap from an electrode or tool, which serves as the cathode. The electrolyte, usually a salt solution in water, is pumped through the gap, flushing away metal dissolved from the workpiece. As the electrode tool moves towards the work piece to maintain a constant gap, the workpiece is machined into the complementary shape of the tool.
There is a need for further methods for electrochemical machining, and more particularly, to electrochemical machining employing electrical voltage pulses to drive reduction and oxidation reactions such as for forming nickel-based alloy turbine blades.